Speed-accelerator and propeller-guard.



L. S. WABO.

SPEED ACCELERATOR AND PROPELLER GUARD.

APPLICATION FILED APR. 3, 1912.

1,065,089. Patented June 17, 1913.

LOUIS 5-. W ABO, OF WEST HOB'OKEN, NEW JERSEY.

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Specification-of Letters Patent.

Patented June 17 1913.

Application filed April's, 1912. Serial N0.-688,220.

To all whom it may concern Be it known that 1, Louis S. WABO, a cit-1- zen of the United States, residin at West Hdbdken, in the county of Hudson and State of New Jersey, have invented. certain new and useful Improvements in Speed-Accelerato'r's and Propeller Guards, of which the following is a specification.

The present invention relates to speed accelerators and propeller guards, and more particularly to a device of this character comprising a propeller and specific form of casing surrounding the same, which may be applied to any vessel of ordinary construction, and by means of which the motive power appii'ed to the propeller may be fully utilized in such a manner as to gain speed and economize power.

A primary object of the invention is to provide a propeller for vessels with a casing or jacket surrounding the propeller, by virtue of which construction, the feed of the water to be acted upon by the propeller will be accelerated, and the water will be concentrated or confined in a region immediately adjacent to the propeller, the construction employed tending to prevent the formation of a vacuum around the propeller hub and preventing the motive power applied to the propeller from being wasted, in the centrifugal effect. By this last named action, the water is ordinarily forced for a great distance in a radial direction from the propeller, and by the structure employed, according to the present invention,-

the waste of power resulting from this centrifugal action is prevented.

A further object of the invention is to provide a device of the character set forth which will possess extreme simplicity of the structural parts so that the device may be cheaply manufactured, and to so arrange the parts that the device may be applied to almost any vessel or boat of ordinary construction.

For a full understanding of the present invention, reference is to be had to the following description and to the accompanying drawings, in which- Figure 1 is a view partly in side elevation and partly in central section. Fig. 2 is an end elevation. Fig. 3 is a horizontal longitudinal section through the device.

Throughout the following detail description and on the several figures of the drawings, similar parts are referred to by like reference characters.

Referring particularly to the drawings, 1 indicates the stern of a vessel, 2 the propeller shaft, 3 the shaft casing and 4 the bearings for the propeller shaft. The latter carries at its outer extremity a propeller 5 of known construction, consisting of a hub from which radiate four propeller blades, each of which is set in a plane arranged at about an angle of 45 degrees to the plane of the axis of the propeller.

6 represents the stern post, arranged in the position shown particularly in Fig. 1, and an outer protective casing 7 for the pro peller is secured by means of the flanged portion 8 and fastenings 9 to said stern post, and also to the stern of the vessel.

An inner or main casing 10, which preferably consists of two frusto-conical sections, placed end to end in such a manner as to form a portion 11 of lesser diameter than the inlet and discharge ends of said casing, is arranged within the casing 7. The inner casing 10 may, if desired, be formed in one piece but it must have the portion 11 of re stricted. diameter, and arranged in such relation to the propeller 5 that the portion 11 will be adjacent to the outer ends of the propeller blades. The operative part of the two casings just described is, of course, the inner casing 10 so far as the structure of the casings afi'ects the speed imparted to the vessel 'by the propeller, the outer casing 7 serving merely to brace the inner structure and protecting it so that its peculiar shape may be maintained. As will be seen, particularly from Fig. 3 of the drawings, the discharge end portion of the casing 10 is flared abruptly from the propeller to the extreme edge of the casing, so that while the casing sufficiently confines the outflowing water to prevent formation of lateral streams or vacuum, with the result that a maximum reactive eflect on the casing is obtained and a maximum forward thrust is imparted to the ship, at the same time the exit for the water is free and offers no frictional resistance to the rearward discharge, as would be true if the casing were extended into a cylinder beyond the flare.

A vertical brace 12 is connected with the stern post 6 in any desired manner and is connected at its lowerend 13 with the easings before described in such a manner as to maintain the latter in the desired position. Cross biaces 1t connect with the brace 12 and are connected at their opposite ends with the outer ends of the casings, the braces 12 and 14 serving not only to strengthen the casings but also to prevent the entrance of obstacles which might interfere with the action of the propeller blades. At the inlet end of the casings, braces 15 are provided for holding the propeller casing in the desired position, and are connected at their ends 16 to the casing and at 17 to the stern of the vessel. Further braces 18 connect the casings 7 and 10 with the casing 3, which houses the propeller shaft.

The operation and advantages of the invention will be readily understood from the foregoing description, and it will be seen that when the vessel moves forwardly, the

water will be fed through the inlet side of the casing 10 at a speed which will be accelerated owing to the restricted portion 11 of the casing 10. By the latter means, the water will be confined .or concentrated in the immediate vicinity of the propeller, the formation of a vacuum in the region of the hub will be prevented, and all loss of force due to the formation of tangential currents will be obviated. Thus there will be but little loss of motive power applied to the pro peller with a resultant great increase in the speed attained. One fact which renders the device particularly efficient is that the restricted portion 11 of the casing 10 very closely approaches the outer ends of the propeller blades. I have found that by virtue of this construction, the speed of the incoming water is somewhat decreased at the restricted portion and the greatest possible amount of water is available for action on the part of the propeller on account of the blades of the same closely approaching such restricted portion. Immediately after being acted upon by the propeller, the water is discharged at the outer end of the casing 10 with a slightly increased speed, which is most desirable for obtaining the best rate of speed for the vessel and due to the fact that the discharge end of the casing is only a short distance away from the propeller, as will be seen in Fig. 1.

In practice, in order to secure from the structure herein described the highest efficiency as to speed, the restricted portion 11 of the casing 10 shall have a diameter equal to, or a little less than the diameter of the propeller, the propeller being disposed a slight distance to the rear of such restricted portion so as to be capable of free rotation in the casing.

Having thus described the invention,what is claimed as new is:

The combination with a screw propeller, of a casin surrounding the same, braces extendin orwardly from the casing and adapte to be fixed to the stern of a vessel, a casing for the shaft of the propeller, braces fixed to the first mentioned casin and connected with the second mentioned casing, a brace pendent from the stern post of the vessel. and extending vertically across the rear of the first mentioned casing, and horizontal braces extending from the edges of the first mentioned casing to and connected with the vertical brace.

In testimony whereof I aflix my signature in presence of two witnesses.

LOUIS s. WABO.

Witnesses:

PETER C. SCHULTZ, WM. M. SCHULTZ. 

